Problem: Express as a common fraction:         $\cfrac{ \frac{2}{5}+\frac{3}{4} }{ \frac{4}{9}+\frac{1}{6}}$.
Answer: We have $$\cfrac{ \frac{2}{5}+\frac{3}{4} }{ \frac{4}{9}+\frac{1}{6}}=\cfrac{ \frac{8+15}{20} }{ \frac{8+3}{18}}=\frac{23}{20} \times\frac{18}{11}=\frac{23}{\cancelto{10}{20}}\hspace{4mm}\times \frac{\cancelto{9}{18}}{11} =\boxed{\frac{207}{110}}.$$